Researchers from Carnegie Mellon University and Disney Research Pittsburgh are pioneering a new frontier for 3D printing in which soft, malleable objects such as teddy bears can be conjured up out of a little imagination and a few clicks of a mouse. This development was made possible by the invention of a new 3D printer that hybridized the old hard-plastic printer with a sewing machine. The ability to print teddy bears and other soft, warm-and-fuzzy objects is still in the development phases, but will potentially open up a new slew of 3D printed applications for both solely soft products and objects with mixed hard and soft parts.
Just like printing a page from a digital file using a two-dimensional printer, a 3D printer uses digital files to create objects. Since its invention in 1983, both professionals and hobbyists alike have used 3D printing to create everything from fine art and toys to guns and human tissue implants.
In the past, a major limiting factor for 3D printing was the materials available to act as the printer’s “ink.” In the early days, the plastics used to produce objects were notoriously brittle and would easily break. In addition, the progressive cooling of the plastics from a liquid to a solid phase meant that objects were liable to shrink and irregularly distort. However in the subsequent years, particularly since 2010, materials science has bounded forward to meet the demands of imaginative designers. Some of the latest highlights include printing droplets of sugary liquid that can be spherified into printed “fruit,” structural steel elements for construction and gelatinous matrices used to create new human tissues and organs.
While 3D printing technology may now have a solid foot-hold on working with fluid, rigid, or gelatinous materials, a hitherto unexplored frontier has been that of soft, fabric-like materials. A new machine invented by researchers at Carnegie Mellon University and Disney Research Pittsburgh is pushing the envelope to produce familiar, soft and cuddly objects like teddy bears.
As with a normal 3D printer, the first step is to design the teddy bear or other object using 3D modeling software. Once ready, the object is fabricated by layering woolen fibers over a sheet of felt. The strands of yarn are further secured using a barbed tool that employs a needle felting technique. The needle pierces into the fabric and upon being dragged backwards, the fibers from the inside layers tangle and mash together to create both a secure structure and a pleasantly soft texture.
Though printing teddy bears may seem like a modest way to kick-start an innovative industry, the researchers have many ideas for future applications. For example, recently there has been an increasing interest in “soft robotics,” a sub-field of robotic engineering that seeks to introduce soft and deformable structures to an otherwise rigid discipline. Such malleable structures would give a robot greater flexibility and capacity to sense and respond to the environment.
By Sarah Takushi